Surging at low speed low throttle?

So, kind of a weird thing happening with the Tundra in my driveway. My driveway is about 30’ long and at a pretty good angle - call it 25 degrees. I usually pull in off the street, wait for the garage door to go up and then pull into the garage. Often, the Tundra will start to pull slowly into the garage with light throttle, and then after a few feet it will surge a bit, almost like I’m blipping the throttle, but I’m not. I don’t know if it’s a torque converter thing or a transmission thing or a traction thing - it could literally be slipping on all the tire cleaner that’s on my driveway, I don’t know. My Tacoma never did this, and my 5.0 Mustang had enough torque to climb up my driveway with no throttle. But this is my first full size truck.

Anyone else noticed anything like this? 6k miles on the truck, been doing it since new.